1. Field of the Invention
The present disclosure relates to a liquid crystal display (LCD) device, and more particularly, to a three dimensional liquid crystal display device (3D LCD device) which facilitates to improve a picture quality of a three-dimensional image (3D image) by color and luminance corrections, and a method for driving the same.
2. Discussion of the Related Art
An LCD device includes a liquid crystal panel on which plural liquid crystal cells are arranged in a matrix-type configuration; a backlight unit which supplies light to the liquid crystal panel; and a driving circuit which drives the liquid crystal panel. The LCD device displays an image by controlling a transmittance pixel-by-pixel in accordance with an input video signal.
On the liquid crystal display panel, there are the plural liquid crystal cells defined by crossing a plurality of gate lines and a plurality of data lines. Each liquid crystal cell is provided with pixel electrode and common electrode for applying an electric field. Each of the liquid crystal cells is switched through a thin film transistor (TFT).
The driving circuit includes a gate driver (G-IC) for supplying a scan signal to the gate lines; a data driver (D-IC) for supplying a data voltage based on an image signal to the data lines; a timing controller (T-con) for supplying a control signal to the gate driver and data driver, and supplying image data to the data driver; and a backlight driver for driving a light source (backlight) supplying light to the liquid crystal panel.
In the LCD device, an alignment of liquid crystal is changed depending on a voltage formed between the pixel electrode and the common electrode pixel-by-pixel. Thus, the transmittance of light emitted from the backlight can be controlled through the alignment of liquid crystal, to thereby display the image.
Recently, a user's demand for a stereoscopic image is rapidly increased so that an LCD device capable of displaying 3D (3-dimensional) image as well as 2D (2-dimensional) image is actively developed.
The LCD device displaying 3D image can realize the 3D image through a difference in viewing between both eyes of the user (binocular parallax display). There have been proposed a shutter glass method using stereoscopic glasses, a patterned retarder method using polarizing glasses, and a lenticular lens method.
FIGS. 1 and 2 illustrate a method of realizing a 3D image by a related art shutter glass method.
Referring to FIGS. 1 and 2, the method of realizing a 3D image by the related art shutter glass method uses a difference in viewing between both eyes of the user through the use of shutter glass 20. After 2D left-eye image and 2D right-eye image, which are different from each other, are viewed by the left and right eyes of the user, two of the 2D images are integrated, whereby the integrated image is perceived as the 3D image by the user.
For this, a liquid crystal panel 10 separately displays 2D images for the left-eye viewing and right-eye viewing with a difference in time. Through the use of shutter glass 20, the right-eye viewing is intercepted and the 2D image is viewed by the left eye when the 2D image for the left-eye viewing is displayed on the liquid crystal panel 10; and the left-eye viewing is intercepted and the 2D image is viewed by the right eye when the 2D image for the right-eye viewing is displayed on the liquid crystal panel 10.
Thus, after the different 2D images are respectively viewed by the left eye and the right eye with the different in time, the viewed 2D images are integrated so that the integrated image is perceived as the 3D image by the user.
In case of the related art LCD device, the 3D image is realized by switching on/off the shutter glass 200 under the circumstance that the 2D images for the left-eye viewing and right-eye viewing are alternately displayed for a preset time period (1 frame).
While the light emitted from the liquid crystal panel 10 passes through the shutter glass 20, there is the image distortion. As shown in FIG. 3, the image is distorted in two aspects, that is, color distortion and luminance reduction.
In more detail, it is possible to switch on/off left-eye lens and right-eye lens of the shutter glass 20 through the use of light crystal. When the light emitted from the liquid crystal panel 10 passes through the shutter glass 20 on the basis of the light transmittance property of the liquid crystal, the light transmittance difference occurs depending on the light wavelength.
For example, supposing that the shutter glass 20 has the relatively-low transmittance for the blue-colored light, and the relatively-high transmittance for the red-colored light and green-colored light. In this case, the original color of the image is distorted to the yellowish color. This color distortion caused by the shutter glass 20 may deteriorate the picture quality of the 3D image.
Like the liquid crystal panel 100, the shutter glass 20 includes a light crystal layer, whereby it has the low light transmittance. Thus, while the light emitted from the liquid crystal panel 10 pass through the shutter glass 20, the luminance of the image is reduced, thereby deteriorating the picture quality of the 3D image.